A vertebral compression fracture occurs when the bones of the spine become broken due to trauma. Methods to strengthen vertebral bodies have evolved with significant clinical improvement for affected patients. A common procedure is vertebroplasty in which a bone substitute or bone cement (e.g., polymethylmethacrylate, hydroxylapatite compound or other material such as bone bits or bone filler of various types) is injected directly into the vertebral body. Kyphoplasty is a variation of a vertebroplasty which attempts to restore the height and angle of kyphosis of a fractured vertebra (of certain types), followed by its stabilization using injected bone cement. The procedure typically includes the use of a small balloon that is inflated in the vertebral body to restore the original vertebral body anatomy prior to cement delivery. When the catheter balloon is deflated, a cavitary void remains, which is then filled with materials similar to the vertebroplasty. While both procedures can have significant benefit for the patient, they are not without potential adverse effects. Once injected, bone cement is an inorganic material that acts as a foreign body, and thus, does not allow for complete healing, but may instead lead to bone disease. Additionally, bone cement is typically stiffer than bone, which may increase the incidence of adjacent level fractures in the spine. Also, bone cement leakage outside of the vertebral body may cause complications such as infection, bleeding, numbness, tingling, headache, and paralysis.
Thus, there remains a need for safe and effective kyphoplasty materials and procedures for treating collapsed or compressed vertebral bodies.